AMBIO, 20, 7, 1991, pp. 298-302
This study covers the Chittaurgarh irrigation project, situated in the outer Indian Himalayas. The main purpose of the study was to assess the positive and negative impacts of the ongoing project, on the physical, biological, socioeconomic and cultural environments and to ensure the continuation of natural resources.
The construction of a dam and canals have had a serious impact on flora and fauna in this project. Agricultural and grazing lands have been lost by utilization of 405 ha Himalayan forest-land upstream and 212 ha of cultivated land downstream of the project. Impacts expected after canal operation include: rise in watertable; waterlogging; increased salinity, due to clay dominated soils with low permeability, and high watertable (0.43 m) during post-monsoon period; fuelwood and fodder crises due to deforestation in the catchment area; weed infestation, crop pests; and human diseases, e.g. malaria, poliomyelitis, filariasis and goitre.
Positive impacts include: flood control, increase in agricultural production (mainly rice, 25,330 t/yr-1) and improvement in socioeconomic conditions.
The investigations made on Chittaurgarh Irrigation Project clearly indicate that negative impacts are of serious concern.
The following guidelines have been proposed to eliminate the negative impacts of irrigation projects to ensure ecologically sustainable development.
- The catchment area in the watershed upstream of the dam should be afforested by mixed vegetation of native species mainly Haldu (Adina cordifolia), Shisham (Dalbergia sissoo), Khair (Acacia catechu), Teak (Tectona grandis) with good shrub cover to reduce erosion.
- Silt loads should be trapped before reaching the dam in order to eliminate sedimentation problems. The whole dam should be afforested with fast-growing trees like Eucalyptus camadulensis and Eucalyptus globulus, to absorb moisture; Populus ciliata for fodder and fuelwood, and Acacia nilotica with good cover of grasses, viz. Cynodon dactylon, Vetivera zizaniodes, Dichanthium annulatum for binding soil particles and checking erosion.
- The tree belt should be developed at an appropriate location on the canal embankment. Plantations should be introduced on the basis of the needs of the location. If a canal is close to a village, the tree belt should be planted to fulfil the requirements of fuelwood and fodder of the villagers. Strict regulations should be set for the cutting of trees; only mature trees should be cut. Subsidized alternative fuels should also be arranged to reduce dependence on trees. Planting trees on the canal bunds, besides yielding fuelwood and fodder, will help to suppress excessive growth of species like Typhia augustifolia and Eichhornia crassipes. The most suitable tree species are Populus ciliata, Dalbergia sissoo, and Acacia nilotica.
- Tanks and equalizing reservoirs should be carried out as an additional project and should be developed at appropriate locations in the area.
- Some of the low-lying swampy areas are unfit for agriculture and should be developed for fisheries. Cyprinid species are best suited for the area.
- The indiscriminate use of insecticides and fertilizers should be minimized in the project area. Integrated pest management (IPM) strategies should be popularized among farmers.
- A suitable infrastructure, involving the participation of farmers should be developed, such as irrigation cooperatives at village level for the distribution of water, at the microlevel, and for water management in general.
- Proper infrastructural facilities should be developed to meet the requirements of increased crop production which result from intensive irrigation farming. This includes farm power (electricity), seeds/seedlings, fertilizers, crop processing, storage, transport, marketing, rural credit, etc.
- Complementary education and training programs should be introduced for all professional levels involved in water management. High priority should be given to improving the understanding of decision-makers, including mid-level and senior officials, in regard to the special problems of water management. Public awareness should be improved in the villages through education of farmers and villagers.
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